1. Field of the Invention
The present invention relates to a rear portion structure of a vehicle and, more particularly, to a rear portion structure of a vehicle, which can increase the coupling strength between rear side frames of a kick-up frame structure and a rear suspension cross member, and can reinforce kick-up portions of the rear side frames.
2. Description of the Related Art
Conventionally, a frame structure, called a kick-up frame structure, is known. In this structure, a frame is bent upward at a portion where the rear axle is arranged so as to attain a low-floor structure. The kick-up frame structure is applied not only to buses having a frame structure but also to passenger vehicles. Especially in a passenger vehicle, the following technique is known. That is, a pair of right and left rear side frames arranged at the right and left side portions of a rear portion of a vehicle body adopt a kick-up frame structure, and the pair of right and left rear side frames are coupled and fixed through a rear suspension cross member. More specifically, a kick-up portion, which is inclined upward toward the back, is formed on an intermediate portion of each of the right and left rear side frames. The rear suspension cross member is fastened by bolts to the lower surfaces of rear portions of the kick-up portions of the right and left rear side frames using attaching holes formed in the right and left end portions of the rear suspension cross member.
A spare tire storage portion for storing a spare tire is arranged near the rear end portion of a vehicle as a side behind the rear suspension cross member. In addition, a fuel tank is normally arranged below the kick-up portions at the passenger room side as a side in front of the rear suspension cross member. When a vehicle is a rear-wheel drive vehicle or a four-wheel drive vehicle, a differential device or the like is arranged behind the rear suspension cross member. The above-mentioned structure is a popular structure employed in a rear portion structure of a conventional vehicle.